Infectious Disease Prevention and Control · data needs of SWPH’s Infectious Disease Prevention & Control team. The information included in this report may assist in program planning

Infectious Disease Prevention and Control Health Status by Program Area

Population Health Assessment

Southwestern Public Health

June 2019

Authors

Hadia Hussain, MPH

Epidemiologist/Program Evaluator

Foundational Standards


Melissa MacLeod, M.Sc.

Epidemiologist

Foundational Standards


Acknowledgements

We would like to thank the Infectious Disease Prevention and Control team for their

engagement as well as our reviewers:

• Cara-Lee Coghill, Public Health Nurse, Infectious Disease Prevention and Control

• Robyn Latendresse, Public Health Nurse, Infectious Disease Prevention and Control

• Laura Gibbs, Program Manager, Foundational Standards

• Elaine Reddick, Program Manager, Infectious Disease Prevention and Control

• Susan MacIsaac, Program Director, Infectious Disease Prevention and Control

• Cynthia St. John, Chief Executive Officer (CEO)

How to cite this document:

Hussain H, MacLeod M. Infectious disease prevention and control: health status by program

area. Southwestern Public Health; 2019.

Contents

Summary ................................................................................................................................... 1

Vaccine Preventable Diseases ................................................................................................... 2

Influenza ................................................................................................................................. 2

Pertussis ................................................................................................................................ 9

Varicella ................................................................................................................................10

Invasive Pneumococcal Disease ...........................................................................................11

Other Infectious Diseases .........................................................................................................13

Invasive Group A Streptococcal Disease ...............................................................................13

Tuberculosis ..........................................................................................................................14

Reportable Incidents .................................................................................................................15

Adverse Events Following Immunization ...............................................................................15

Cold Chain Incidents .............................................................................................................16

References ...............................................................................................................................18

Appendix A: Technical Notes ....................................................................................................20

Integrated Public Health Information System (iPHIS) .............................................................20

National Ambulatory Care Reporting System (NACRS) .........................................................20

Canadian Community Health Survey (CCHS) ........................................................................21

Population Estimates and Projections ...................................................................................21

Infectious Disease Prevention and Control | 1

Summary

This report is intended to complement the 2019 health status report titled Understanding our

Communities’ Health, which aimed to provide a high-level overview of the current health status

of people residing in the Southwestern Public Health (SWPH) region.1 This report includes many

of the same indicators, but highlights differences by sociodemographic characteristics such as

age, sex, income and education, where possible. These indicators were chosen based on the

data needs of SWPH’s Infectious Disease Prevention & Control team. The information included

in this report may assist in program planning and be used to increase community awareness of

health issues. The data may be used to develop other knowledge translation products as

needed. The overarching trends for each topic are summarized below.

Vaccine Preventable Diseases

• In the SWPH region, a higher percentage of the population living in urban areas reported

getting the seasonal flu shot less than one year ago compared to those living in rural

areas.

• A large proportion of the population who did not receive the seasonal influenza vaccine

did not think it was necessary. Other reasons for not getting the flu shot included a lack

of belief in its benefits, a lack of time, an adverse reaction to previous flu shot and

fear/discomfort.

• Incidence rates for pertussis as well as hospitalization rates for varicella were highest

among children under 5 years of age. The incidence rate for invasive pneumococcal

disease was highest among people aged 65 years and over.

Other Infectious Diseases

• The rates of other infectious disease remain low and comparable to Ontario. The

incidence rate of invasive group A streptococcal disease was higher among people aged

65 years and over compared to those aged 5 to 19 years and 20 to 64 years.


Infectious Disease Prevention and Control

Vaccine Preventable Diseases

The vaccine preventable diseases section of the report includes data about confirmed cases of

influenza and influenza immunization in the community, confirmed cases of pertussis (whooping

cough) and invasive pneumococcal disease, hospitalizations for varicella and reports of adverse

events following immunization. Incidence rates are presented by age, where possible, in order

to emphasize higher risk sub-populations.

The data presented in this report may differ slightly from previous reports; data in the

report titled Understanding our Communities’ Health was age-standardized to

compare local data to Ontario, but the data presented in this report is not age-

standardized and focuses on local differences between subgroups of the population.

Influenza

In the Southwestern Public Health (SWPH) region, there were a total of 220 confirmed cases for

the 2017/2018 influenza season,a with the majority being influenza B cases (56.8%) (Figure 1).

This was different from previous influenza seasons in which most cases were influenza A. There

were three confirmed cases of influenza A and B co-infection in the 2017/2018 influenza season

and none in the previous influenza seasons. There may be co-infected cases present each

season that were not lab confirmed and would not be included in these counts.

a As a result of changes in respiratory virus laboratory testing starting September 20, 2017, some indicators of

respiratory virus will not be comparable to past seasons. Due to discontinued multiplex testing, no routine respiratory virus testing from ambulatory and emergency department patients and no further testing of influenza-positive specimens tested by PCR, the number of confirmed cases detected may be underestimated in the 2017/2018 influenza season compared to previous seasons. Additionally, lab confirmed cases in general are an underestimation of the total number of influenza cases in the population since many cases are seen in outpatient settings or do not seek care.


Figure 1. Count and crude incidence rate (per 100,000 population) of confirmed influenza cases by type, Southwestern Public Health, 2013/2014-2017/2018 influenza seasons

Source: iPHIS (2013-2018), Extracted: February 25, 2019 & Population Estimates (2013-2016), Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: August 9, 2018 & Population Projections (2017), Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: August 9, 2018.

In the 2014/2015, 2016/2017 and 2017/2018 influenza seasons, age-specific rates of influenza

were highest among people age 65 and older, followed by children less than five years of age

(Figure 2). In the 2013/2014 and 2015/2016 seasons, children aged less than five years had the

highest incidence rate of influenza (Figure 2).

The difference in incidence rates may be due to seasonal variations in dominant circulating

strains that have varying high risk age groups (Table 1) as well as changes in the respiratory

virus testing algorithm. For example, since routine testing of specimens from ambulatory or

emergency department settings was no longer offered in the 2017/2018 influenza season, most

specimens under the new algorithm would be from inpatient settings or institutions, which may

inflate the rate of older age groups since they make up a large proportion of these populations.

77

101 95

117

92

40

14

45

16

125

0 0 0 0 3

0

10

20

30

40

50

60

70

0

20

40

60

80

100

120

140

2013/2014 2014/2015 2015/2016 2016/2017 2017/2018

Rate

(per 1

00,0

00 p

opula

tion)

Num

ber

of

new

cases

Influenza A Influenza B Influenza A and B

Influenza A -rate Influenza B -rate


Figure 2. Crude incidence rate (per 100,000 population) of influenza by age group, Southwestern Public Health, 2013/2014-2017/2018 influenza seasons

Source: Public Health Ontario. Infectious disease query. Toronto, ON: Ontario Agency for Health Protection and Promotion (Public Health Ontario), Date Extracted: September 6, 2018 & Population Estimates (2013-2016), Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: August 9, 2018 & Population Projections (2017), Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: August 9, 2018.

People aged 65 and older had the highest incidence rate and represented the largest proportion

of cases during the 2014/2015, 2016/2017 and 2017/2018b influenza seasons (Figures 2 and 3).

Although the incidence rate of influenza was highest among children under five years of age

during the 2013/2014 and 2015/2016 influenza season, people aged 20 to 64 years represented

the largest proportion of cases during those seasons.

b Recent changes in the testing algorithm may affect these rates.

2013/2014 2014/2015 2015/2016 2016/2017 2017/2018

<5 178.5 42.5 126.7 134.4 117.6

5-19 21.0 26.4 69.1 34.7 26.7

20-64 53.9 24.8 55.5 36.7 36.5

65+ 74.0 203.8 95.0 166.0 403.0

0

100

200

300

400

500

Age-s

pecific

rate

(p

er

100,0

0 p

opula

tion)


Figure 3. Proportion of influenza cases by age group, Southwestern Public Health, 2013/2014-2017/2018 influenza seasons

Source: Public Health Ontario. Infectious disease query. Toronto, ON: Ontario Agency for Health Protection and Promotion (Public Health Ontario), Date Extracted: January 4, 2019

Table 1. Dominant circulating strains by influenza season, Ontario, 2013/2014-2017/2018 influenza seasons2-6

Influenza Season Influenza A Strain Influenza B Strain

2013/2014 H1N1pdm09 B/Massachusetts/02/2012

2014/2015 H3N2 B/Massachusetts/02/2013

2015/2016 H1N1pdm09 B/Brisbane/60/2008- like

2016/2017 H3N2 B/Phuket/3073/13-like

2017/2018 H3N2 B/Phuket/3073/13-like

The influenza season with the highest number of institutional influenza outbreaks was

2017/2018, followed by 2014/2015 (Figure 4). The variations in institutional outbreaks may be

due to different circulating strains each season, variations in vaccine effectiveness from season

to season and immunization coverage of the populations within these institutions.

2013/2014 2014/2015 2015/2016 2016/2017 2017/2018

<5 18% 4% 11% 12% 6%

5-19 7% 9% 19% 10% 5%

20-64 54% 25% 46% 32% 20%

65+ 21% 62% 24% 46% 70%

0%

20%

40%

60%

80%

100%


Figure 4. Number of institutional influenza outbreaks by season, Southwestern Public Health, 2013/2014-2017/2018

Source: iPHIS (2013-2017), Date Extracted: January 24, 2019

Influenza immunization

In the SWPH region, the proportion of the population that reported getting the seasonal flu shot

in the past 12 months was similar between males and females (Figure 5). There was also no

difference in the proportion people reporting getting the seasonal flu shot less than one year ago

by household income and education level.

Figure 5. Proportion of population who reported getting the seasonal flu shot in the past 12 months by sex, Southwestern Public Health, 2015-2016

Source: Canadian Community Health Survey (2015-2016), Statistics Canada, Share File, Ontario MOHLTC.

72 1

203 19

18

10

2

0

10

20

30

40

2013/2014 2014/2015 2015/2016 2016/2017 2017/2018

Influenza B Influenza A Influenza A and B

39.1%

31.1%

0% 10% 20% 30% 40% 50%

Females

Males


The proportion of people in the SWPH region who reported getting the seasonal flu shot in the

past 12 months was not statistically significantly different between people with a regular health-

care provider compared to those without a regular health-care provider (Figure 6).

Figure 6. Proportion of population who reported getting the seasonal flu shot in the past 12 months by health-care provider access, Southwestern Public Health, 2015-2016

Source: Canadian Community Health Survey (2015-2016), Statistics Canada, Share File, Ontario MOHLTC

The proportion of the population who reported getting the seasonal flu shot in the past 12

months was higher among those living in the urban municipalities of the SWPH region

compared to the rural municipalities (Figure 7). This difference between urban and rural

municipalities may be due to differences in access to health care or differences in beliefs about

the influenza vaccine (flu shot).

Figure 7. Proportion of the population who reported getting the seasonal flu shot in the past 12 months by urban or rural residence, Southwestern Public Health, 2015-2016

Source: Canadian Community Health Survey (2015-2016), Statistics Canada, Share File, Ontario MOHLTC

23.5%

35.6%

0% 10% 20% 30% 40%

No regular health-care provider

Regular health-care provider

From 2015 to 2016, 39.9% (95% CI: 35.2%-44.8%) of the population living in the

urban municipalities (i.e., St. Thomas, Aylmer, Ingersoll, Tillsonburg and

Woodstock) reported getting the seasonal flu shot in the past 12 months.

From 2015 to 2016, 28.1% (95% CI: 23.3%-33.5%) of the population living in

the rural municipalities (i.e., Bayham, Central Elgin, Southwold,

Dutton/Dunwich, Malahide, West Elgin, Blandford-Blenheim, East Zorra-

Tavistock, Zorra, Norwich and South-West Oxford) reported getting the

seasonal flu shot in the past 12 months.


Reasons for not getting the flu shot

Approximately half (48.6%) of the population in the SWPH region that did not get the flu shot in

the past 12 months reported that they made this decision because they did not think it was

necessary and almost one-fifth (17.4%) did not believe in its benefits (Figure 8). Other reasons

for not getting the flu shot in the past 12 months were lack of time, an adverse reaction to

previous flu shot and fear or discomfort.

Figure 8. Reasons for not getting the seasonal flu shot in the past 12 months, Southwestern Public Health, 2015-2016

* Interpret with caution due to high variability.

Source: Canadian Community Health Survey (2015-2016), Statistics Canada, Share File, Ontario MOHLTC.

4.7%*

7.4%*

12.9%

17.4%

48.6%

0% 10% 20% 30% 40% 50% 60%

Fear/discomfort

Bad reaction to previous flu shot

Lack of time

Does not believe in benefits

Didn’t think it was necessary


Pertussis

The rates of pertussis (whooping cough) in the SWPH region follow a cyclical pattern with

outbreaks occurring approximately every three to four years (Figure 9). The peaks in the rate of

pertussis coincide with the three outbreaks that have occurred since 2008, although all cases

(sporadic and outbreak cases) are included in these estimates.

Figure 9. Crude incidence rate (per 100,000 population) of confirmed cases of pertussis, Southwestern Public Health, 2008-2018

Source: Public Health Ontario. Infectious disease query. Toronto, ON: Ontario Agency for Health Protection and Promotion (Public Health Ontario), Date Extracted: January 4, 2019 & Population Estimates (2013-2016), Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: August 9, 2018 & Population Projections (2017-2018), Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: August 9, 2018.

The incidence rate of pertussis was highest among children under five years of age, followed by

people aged 5 to 19 years (Figure 10). There was a sharp increase in the age-specific rates for

the younger age groups in 2017, which corresponds to an outbreak of pertussis in the

community.

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018

SWPH 1.5 53.0 1.0 25.7 55.0 20.9 3.0 0.0 10.8 72.7 12.1

0

25

50

75


Figure 10. Crude incidence rate (per 100,000 population) of pertussis by age group, Southwestern Public Health, 2013-2018

Source: Public Health Ontario. Infectious disease query. Toronto, ON: Ontario Agency for Health Protection and Promotion (Public Health Ontario), Date Extracted: January 4, 2019 & Population Estimates (2013-2016), Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: August 9, 2018 & Population Projections (2017), Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: August 9, 2018.

Varicella

Age-specific rates of emergency department (ED) visits due to varicella (chicken pox) were

consistently highest among children under five years of age between 2013 and 2017, followed

by people aged 5 to 19 years (Figure 11). The incidence rate among children under five years of

age appears to be decreasing over time but the rate among people aged 5 to 19 years seems

relatively stable. The decrease could be attributed to the 2011 expansion to a two-dose

immunization schedule for varicella and the addition of varicella to the Immunization of School

Pupils Act (ISPA) for children born in 2010 or later.7 Because only a small proportion of cases

are seen in an ambulatory setting, these rates are likely an underestimate of the true rate of

varicella in the population because they do not include cases that were seen in primary care or

those that did not seek care.

2013 2014 2015 2016 2017 2018

<5 153.0 8.5 0.0 117.6 554.3 100.8

5-19 31.6 2.6 0.0 16.0 187.1 24.0

20-64 8.5 3.4 0.0 1.7 9.3 3.4

65+ 3.0 0.0 0.0 0.0 0.0 0.0

0

100

200

300

400

500

600

Age-s

pecific

rate

(p

er

100,0

00 p

opula

tion)


Figure 11. Crude incidence rate (per 100,000 population) of emergency department visits due to varicella by age group, Southwestern Public Health, 2013-2017

Source: National Ambulatory Emergency External Cause (2013-2017), IntelliHEALTH ONTARIO, Ontario Ministry of Health and Long-Term Care, Date Extracted: September 17, 2018 & Population Estimates (2013-2016), Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: August 9, 2018 & Population Projections (2017), Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: August 9, 2018.

Invasive Pneumococcal Disease

In 2017, there were 9.3 cases of invasive pneumococcal disease (IPD) per 100,000 population,

which has remained similar over time (Figure 12). Of those cases with a known immunization

status between 2013 and 2017, 49% were up to date on their vaccination.c Because 40% of

cases were excluded from the calculation due to an unknown immunization status, this

proportion may be inflated.

c This proportion does not take serotype into account, meaning it is unable to determine whether those who were

vaccinated contracted a non-vaccine serotype.

2013 2014 2015 2016 2017

<5 195.5 135.9 194.2 109.2 50.4

5-19 55.3 42.3 31.9 48.0 37.4

20-64 9.4 3.4 4.3 4.3 4.2

65+ 8.9 11.5 5.6 2.7 2.6

0

50

100

150

200

250

Age-s

pecific

rate

(p

er

100,0

00 p

opula

tion)


Figure 12. Crude incidence rate (per 100,000 population) of confirmed cases of invasive pneumococcal disease, Southwestern Public Health, 2008-2017

Source: Public Health Ontario. Infectious disease query. Toronto, ON: Ontario Agency for Health Protection and Promotion (Public Health Ontario), Date Extracted: January 4, 2019.

The incidence rate of invasive pneumococcal disease between 2013 and 2017 was highest

among people aged 65 years and older (Figure 13).

Figure 13. Crude incidence rate (per 100,000 population) of invasive pneumococcal disease by age group, Southwestern Public Health, 2013-2017 (combined)


5.6

9.710.6

11.612.0

6.0

7.9

9.9

11.8

9.3

0

5

10

15

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

5.1 3.26.7

24.0

0

10

20

30

40

<5 5-19 20-64 65+


Other Infectious Diseases

Invasive Group A Streptococcal Disease

In 2017, the rate of invasive group A streptococcal disease (iGAS) was 8.3 per 100,000

population (Figure 14). Overall, the rate of iGAS in the SWPH region increased slightly from

2008 to 2017. Of the cases with known risk factors, the most commonly reported risk factor was

chronic illness or underlying medical condition (65.1%). This was followed by reporting a

dermatological condition, chronic dermatitis or a condition that would causing a break in skin

integrity (61.9%), diabetes (35.1%) and compromised immune response (18.8%).

Figure 14. Crude incidence rate (per 100,000 population) of confirmed cases of invasive group A streptococcal disease, Southwestern Public Health, 2008-2017

Source: Public Health Ontario. Infectious disease query. Toronto, ON: Ontario Agency for Health Protection and Promotion (Public Health Ontario), Date Extracted: January 4, 2019.

The rate of iGAS was higher among those aged 65 years and older compared to those aged 5

to 19 years and 20 to 64 years (Figure 15). This difference may be due to increased prevalence

of chronic diseases and underlying medical conditions, which are commonly reported risk

factors among iGAS cases.8

2.02.5

3.03.5 3.5 3.5

5.5 5.4

2.5

8.3

0

2

4

6

8

10

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017


Figure 15. Crude incidence rate (per 100,000 population) of invasive group A streptococcal disease by age group, Southwestern Public Health, 2008-2017 (combined)


Tuberculosis

Overall, there were 10 cases of tuberculosis between 2013 and 2017, of which seven completed

treatment and three did not complete treatment due to death or non-compliance. Most treatment

(for 80% of the cases) was administered using directly observed therapy (DOT).9

TB-drug resistance remains low in the SWPH region. Among the isolates tested for TB in the

SWPH region between 2013 and 2017, one exhibited drug resistance to pyrazinamide and the

remaining were sensitive to all four first-line TB drugs: isoniazid, pyrazinamide, rifampin and

ethambutol.9 There was one confirmed case which exhibited isoniazid resistance in 2018.

Latent tuberculosis

On average, there were approximately 35 cases of latent tuberculosis infection (LTBI) reported

to SWPH each year between 2013 and 2017. The crude rate of LTBI in the SWPH region was

17.7 per 100,000 population (95% CI: 15.2-20.5) during that time.9

6.0

1.33.4

8.4

0

4

8

12

16

<5 5-19 20-64 65+


Reportable Incidents

Adverse Events Following Immunization

The overall adverse events following immunization (AEFI) reporting rate from 2013 to 2017 was

6.5 reports per 100,000 population (95% CI: 5.0-8.3; Figure 16). Although there were annual

fluctuations in the number of AEFI reports, there have been no unusual increases to the rate; it

remains low and relatively consistent from year to year.

Figure 16. Number of AEFI reports and reporting rate (per 100,000), Southwestern Public Health, 2012-2017

Source: Ontario Agency for Health Protection and Promotion (Public Health Ontario). Vaccine safety surveillance [Internet]. Toronto, ON: Queen’s Printer for Ontario; 2018 [cited 2019 January 16]. Available from: http://www.publichealthontario.ca/en/DataAndAnalytics/pages/aefi.aspx.Population Estimates (2013-2016), Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: August 9, 2018 & Population Projections (2017), Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: August 9, 2018.

In the SWPH region, injection site reactions, such as pain/redness/swelling and cellulitis, were

the most reported adverse event (63.6% of all AEFI reports), followed by systemic events

(30.3% of all AEFI reports), which include rash, fever and vomiting/diarrhea (Figure 17).8

Allergic events such as reactions on skin or anaphylaxis represented 24.2% of all AEFI reports.

Only 3% of AEFIs reported neurologic events which included anaesthesia/paraesthesia and

convulsions/seizures.10

18

8

11

15 14

18

0

2

4

6

8

10

0

4

8

12

16

20

2012 2013 2014 2015 2016 2017

Reportin

g ra

te(p

er 1

00,0

00 p

opula

tion)N

um

ber

of

AE

FI

report

s

AEFI reports AEFI reporting rate

http://www.publichealthontario.ca/en/DataAndAnalytics/pages/aefi.aspx


Around 37% of AEFIs were reported by a physician or nurse practitioner, 23.9% were reported

by family members and 22.4% were reported by other health care professionals. Only 3% of

AEFIs were self-reported.

Figure 17. Per cent of all AEFI reports by adverse event type, Southwestern Public Health, 2013-2017 (combined)

Source: iPHIS (2013-2017), Date Extracted: January 24, 2019

Cold Chain Incidents

The number of cold chain incidents appears to have increased slightly over time since 2016

(Figure 18). The most common cause of cold chain incidents between 2016 and 2018 was due

to equipment or refrigerator/freezer malfunctions, accounting for 25.3% of all incidents. This was

followed by human error (20.7%) which includes improper storage, refrigerator/freezer doors left

open and an unmonitored refrigerator/freezer.

3.0%

21.2%

24.2%

30.3%

63.6%

0% 20% 40% 60% 80%

Neurologic events

Other severe/unusual events

Allergic events

Systemic events

Injection site reactions


Figure 18. Number of Cold Chain Incidents by year, Southwestern Public Health, 2016-2018

Source: PEAR (2016-2018), Date Extracted: March 5, 2019

From 2016 to 2018, the largest proportion of cold chain incidents occurred in long-term care

homes (Figure 19). This was followed by group-practice clinics, pharmacies, hospitals and solo-

practice clinics.

Figure 19. Proportion of cold chain incidents by setting, Southwestern Public Health, 2016-2018 (combined)

Source: PEAR (2016-2018), Date Extracted: March 5, 2019

22

33 32

0

10

20

30

40

2016 2017 2018

8.1%

9.3%

10.5%

15.1%

37.2%

0% 10% 20% 30% 40%

Physician, solo-practice

Hospital

Pharmacy, flu client

Physician, group-practice

Long term care home


References

1. MacLeod M, Hussain H. Understanding our communities’ health: current health status of

people residing in the Southwestern Public Health region. Southwestern Public Health;

2019.

2. Public Health Ontario. Ontario Respiratory Virus Bulletin | 2013-2014. Toronto, ON; Queen’s

Printer for Ontario; 2014. Available from:

https://www.publichealthontario.ca/en/DataAndAnalytics/Documents/Ontario_Respiratory_Vi

rus_Bulletin-2013-2014_Season_Summary.pdf



https://www.publichealthontario.ca/en/DataAndAnalytics/Documents/Ontario_Respiratory_Vi

rus_Bulletin-2014-2015_Season_Summary.pdf



https://www.publichealthontario.ca/en/DataAndAnalytics/Documents/Ontario_Respiratory_P

athogen_Bulletin-Season_Summary_-_2015-16.pdf



https://www.publichealthontario.ca/en/DataAndAnalytics/Documents/Ontario%20Respiratory

%20Pathogen%20Bulletin%20-Season%20Summary%20-%202016-17.pdf



https://www.publichealthontario.ca/en/DataAndAnalytics//Documents/Ontario%20Respirator

y%20Pathogen%20Bulletin%20-%20Season%20Summary%20-%202017-18.pdf

7. Ontario Ministry of Health and Long-Term Care. Two-Dose Varicella Immunization

Schedule. Toronto, ON: Queen’s Printer for Ontario. Available from:

http://www.health.gov.on.ca/en/public/programs/immunization/docs/qa_2dose.pdf

https://www.publichealthontario.ca/en/DataAndAnalytics/Documents/Ontario_Respiratory_Virus_Bulletin-2013-2014_Season_Summary.pdf




https://www.publichealthontario.ca/en/DataAndAnalytics/Documents/Ontario_Respiratory_Pathogen_Bulletin-Season_Summary_-_2015-16.pdf

https://www.publichealthontario.ca/en/DataAndAnalytics/Documents/Ontario_Respiratory_Pathogen_Bulletin-Season_Summary_-_2015-16.pdf

https://www.publichealthontario.ca/en/DataAndAnalytics/Documents/Ontario%20Respiratory%20Pathogen%20Bulletin%20-Season%20Summary%20-%202016-17.pdf

https://www.publichealthontario.ca/en/DataAndAnalytics/Documents/Ontario%20Respiratory%20Pathogen%20Bulletin%20-Season%20Summary%20-%202016-17.pdf

https://www.publichealthontario.ca/en/DataAndAnalytics/Documents/Ontario%20Respiratory%20Pathogen%20Bulletin%20-%20Season%20Summary%20-%202017-18.pdf

https://www.publichealthontario.ca/en/DataAndAnalytics/Documents/Ontario%20Respiratory%20Pathogen%20Bulletin%20-%20Season%20Summary%20-%202017-18.pdf

http://www.health.gov.on.ca/en/public/programs/immunization/docs/qa_2dose.pdf


8. Ontario Agency for Health Protection and Promotion (Public Health Ontario). Invasive Group

A streptococcal disease in Ontario: 2016-17 seasonal summary. Toronto, ON, Queen’s

Printer for Ontario; 2018.

9. iPHIS (2013-2017), Extracted: January 24, 2019 & Population Estimates (2008-2016),

Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: August 9,

2018 & Population Projections (2017), Ministry of Health and Long-Term Care,

IntelliHEALTH ONTARIO, Date Extracted: August 9, 2018

10. Ontario Ministry of Health and Long-Term Care. Appendix B: provincial case definitions for

reportable diseases: adverse events following immunization (AEFIs), 2015. Toronto, ON:

Queen’s Printer for Ontario; 2015. Available from:

http://www.health.gov.on.ca/en/pro/programs/publichealth/oph_standards/docs/aefi_cd.pdf

http://www.health.gov.on.ca/en/pro/programs/publichealth/oph_standards/docs/aefi_cd.pdf


Appendix A: Technical Notes

This section summarizes information from a variety of data sources available to Public Health.

The methods used, and geography presented depends on the data source, described below.

Integrated Public Health Information System (iPHIS)

The Integrated Public Health Information System (iPHIS) is used to report case information on

all reportable communicable diseases for provincial surveillance, as per the Health Protection

and Promotion Act (HPPA). Cases in iPHIS are classified according to the case definitions by

the Ontario Ministry of Health and Long-Term Care (MOHLTC). The data represents only cases

reported to public health and recorded in iPHIS. Therefore, due to differences in medical seeking

and reporting behaviours, there may be some degree of underreporting. iPHIS was used to extract

data regarding confirmed cases of communicable disease in the SWPH region as well as the

number of AEFI reports and type.

National Ambulatory Care Reporting System (NACRS)

NACRS contains information about unscheduled emergency department (ED) visits. The data

submitted by EDs is validated by CIHI and released to public health units on a quarterly basis

through IntelliHEALTH ONTARIO. This information was used to capture ED visits due to

varicella (chicken pox). Table 1 outlines the International Statistical Classification of Diseases

and Related Health Problems, 10th Revision, Canada (ICD-10-CA) codes included for varicella

(chicken pox). These ICD-10-CA codes do not include ED visits for shingles.

Table 1. ICD-10-CA codes used to categorize emergency department visits for varicella2

Description ICD-10-CA codes

Varicella meningitis B010

Varicella meningitis B011

Varicella pneumonia B012

Varicella with other complications B018

Varicella without complication B019


Canadian Community Health Survey (CCHS)

The Canadian Community Health Survey (CCHS) is a national telephone survey that collects

information about health from the population aged 12 years and older. The CCHS excludes

people living on reserves and other Indigenous settlements, full-time members of the Canadian

Forces and people living in institutions. Data is self-reported and may be subject to recall bias

and social desirability bias. ‘Don’t know’ and ‘not stated’ responses were removed from analysis

when they represented less than 10% (combined) of the unweighted sample. This assumes that

data are missing at random, which is not always the case. Data from 2015-2016 onwards is not

comparable to previous years due to substantial changes in sampling methodology and content.

The error bars in figures are the confidence intervals (CIs). Each estimate is based on the

survey sample and a CI is a range of values that describes the uncertainty surrounding an

estimate. The 95% CI shows a range of values that have a 95% chance of including the true

estimate in the population if the survey was repeated. The larger a 95% CI, the more caution

should be used when using the estimate. CIs that don’t overlap show statistically significant

differences between groups. Statistically significant results indicate the finding is unlikely to be

due to chance alone. Only statistically significant differences between groups are presented in

this report.

Population Estimates and Projections

Population estimates and projections were used as the denominator to calculate rates.

Population estimates are produced by the Demography Division at Statistics Canada and were

obtained through IntelliHEALTH ONTARIO.

Southwestern Public Healthwww.swpublichealth.ca St. Thomas Site 1230 Talbot Street St. Thomas, ON N5P 1G9

Woodstock Site 410 Buller Street Woodstock, ON N4S 4N2

http://www.swpublichealth.ca/